Seal for a multipiece wheel assembly

ABSTRACT

A tire rim assembly (16) permits inflation of a tire (10) mounted thereon only when the components constituting the structure are assembled in a locking configuration. The tire rim assembly (16) includes a rim base (18) having first and second grooves (32,34) defined on its outer periphery (30), an annular bead seat member (24) arranged around the rim base (18) and having an inner periphery (38) defining a load transferring surface (42), an inner surface (40), and an inclined ramp surface (44) located between the inner surface (40) and the load transferring surface (42), an elastomeric seal (26) is disposed in the second groove (34), and an annular split lock ring (28) is disposed in axially restraining engagement in the first groove (32) and adapted to contact the load transferring surface (42) of the bead seat member (24) with the structure completely assembled. The elastomeric seal (26) is located by a locking surface (52) of the annular split lock ring (28) and elastically deformed by engagement of the inclined ramp surface (44) to establish an air tight seal between the elastomeric seal (26), the second groove (34), and the inclined ramp surface (44) when the lock ring (28) is properly installed. When the lock ring (28) is omitted or improperly installed the elastomeric seal (26) is free of compression and will not establish an air tight seal.

DESCRIPTION

.Iadd.This is a continuation-in-part application of co-pendingApplication Ser. No. 273,882 filed Nov. 14, 1980 and now abandoned..Iaddend.

1. Technical Field

This invention relates generally to a multiple-piece tire rim assemblyfor mounting large vehicle tires and more particularly to a sealingarrangement that provides sealing between the tire and rim componentsonly when those components are properly installed.

2. Background Art

Large wheels used on vehicles such as earthmoving apparatus are ofmulti-piece construction which permit tires to be mounted thereon andlocked into sealing engagement without the necessity for deforming thetire beads. The beads of a tubeless tire mounted on such multi-piecetire rim structures are axially restrained on one side by a flange whichis either integral with or separate from the rim base and on the otheraxial side by a second flange which is either integral with or separatefrom a bead seat band which is mounted radially between the rim base andthe remaining bead. The bead seat band is locked to the rim base byvarious means and a sealing structure is provided for sealing betweenthe bead seat band and the rim base.

A typical configuration for sealing and locking a tire rim assembly isillustrated in U.S. Pat. No. 3,623,530 which issued Nov. 30, 1971, andis assigned to the assignee of the present invention. A sealing O-ringand lock ring are illustrated in the aforementioned patent and areaxially separated. Such configuration has the potential to permitpartial inflation of the tire if the lock ring is not properly installedor is omitted. U.S. Pat. No. 3,882,919 which issued on May 13, 1975, andis assigned to the assignee of the present invention illustrates anadvance in the art by providing a seal in direct contact with the lockring and having the groove for the seal opening into the groove for thelock ring to enable the seal to be displaced into the lock ring groovein the event that the lock ring is not installed. In the aforementionedpatent, if the lock ring was inadvertently omitted, the seal couldpotentially roll under the bead seat band during inflation due to theaxial length of the seal groove thus allowing the tire to be partiallyinflated. U.S. Pat. No. 2,822,021 illustrates a tire rim assembly havingan axially adjacent and engaged seal apparatus and locking ring whichcooperate to prevent tire inflation if the locking ring is not properlyassembled. However, the apparatus of the aforementioned patent has thedisadvantage of potentially allowing the tire to be partially inflatedin the event the lock ring is not installed. This is possible becausethe seal member can be compressed between the bead seat band and theaxial outer shoulder of the common seal and lock ring groove.

The present invention is directed to overcoming one or more of theproblems as set forth above.

DISCLOSURE OF THE INVENTION

In one aspect of the present invention a multiple-piece tire rimassembly for mounting a tire comprises an annular rim base having anaxial center line and an outer periphery defining first and secondgrooves. The first groove is located in an axially outer portion of theperiphery of the rim base and has a depth greater than the secondgroove. The second groove is located axially inward of the first grooveand opens into an inner side of the first groove. An annular bead seatmember is disposed radially outside the rim base and has an innerperiphery radially adjacent the outer periphery of the rim base. Theinner periphery defines an inner surface, a load transferring surface,and an inclined ramp surface located between the inner surface and theload transferring surface. The load transferring surface extendsradially outward more than the inclined ramp surface. The loadtransferring surface and the inclined ramp surface are respectivelyradially adjacent the first and second grooves. An annular split lockring has a first portion disposed in axially restraining engagement withthe first groove and a second portion in load transferring engagementwith the load transfer surface of the bead seat member. An annularelastomeric seal is disposed in the second groove in axial abutment withthe lock ring for sealing compression of the annular seal in the secondgroove by the inclined ramp surface only when the first portion of thelock ring is fully seated in the first groove and the load transferringsurface of the bead seat member is in contact with the lock ring.

The problem of a tire being partially inflated with the lock ringomitted is overcome by the use of an inclined ramp surface on the beadseat member compressing an elastomeric seal only when the lock ring isfully seated in a groove of a rim base. Thus, if the lock ring isomitted, the inclined ramp surface on the bead seat member pushes theelastomeric seal into the lock ring groove which inhibits the ability ofthe tire to hold air pressure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a radial sectional view through a portion of a tire andassociated rim assembly of an embodiment of the present invention;

FIG. 2 is an enlarged fragmentary view showing the right side only ofthe tire rim assembly of FIG. 1;

FIG. 3 is an enlarged fragmentary view of another embodiment of theinvention; and

FIG. 4 is an enlarged fragmentary view of another embodiment of theinvention.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring now to the drawing in detail, a tire 10 (only a portion ofwhich is shown) has beads 12 and 14 which are mounted on and axiallyrestrained by a tire rim assembly 16 which generally includes an annularrim base 18 having an axial center line 19, a pair of bead restrainingflanges 20,22 respectively, a bead seat member 24 on which tire bead 12is mounted, an elastomeric seal 26 in seal engagement with the bead seatmember 24 and the wheel rim base 18, and an annular split lock ring 28.It is recognized that the first bead restraining flange 20 could be apart of the bead seat member 24 and that the second bead restrainingflange 22 could be part of the rim base 18 as is well known in the art.An air inlet 29 is mounted on the rim base 18 in a conventional mannerto provide a path for air to enter the tire for inflation of the tire10.

As best seen in FIG. 2, the annular rim base 18 has an outer periphery30 defining first and second annular axially adjacent grooves 32,34located in an axially outer portion of the periphery 30 of the rim base18. The first groove 32 has a greater depth than the second groove 34and the second groove 34 is located axially inward of said first groove32. The second groove 34 opens into an inner side of the first groove 32and has a width no greater than one and one half times the diameter ofthe elastomeric seal 26. Preferably the width of the second groove 34 isthe same or slightly larger than the diameter of the elastomeric seal26. The depth of the first groove 32 relative to the outer periphery 30is greater than the diameter of the elastomeric seal 26 while the widthof the first groove 32 is wider than the diameter of the elastomericseal 26.

The annular bead seat member 24 is disposed radially outside the rimbase 18 and has an inner periphery 38 radially adjacent the outerperiphery 30 of the rim base 18. The inner periphery 38 defines an innersurface 40, a load transferring surface 42, and an inclined ramp surface44. The inclined ramp surface 44 is located between the inner surface 40and the load transferring surface 42. The load transferring surface 42extends radially and axially outward more than the inclined ramp surface44. The load transferring surface 42 and the inclined ramp surface 44are respectively radially adjacent the first and second grooves 32,34when the rim assembly is properly assembled. The load transferringsurface 42 is located radially outward such that it would not contactany portion of the elastomeric seal 26 during assembly. The inclinedramp surface 44 is the only portion of the bead seat member 24 thatinitially contacts the elastomeric seal 26 during installation.

The annular split lock ring 28 has a first portion 46 adapted to locatein the first groove 32 and has a seat surface 48 adapted to contact theouter periphery 30 of the rim base 18 in the installed condition. Thesplit lock ring 28 has a second portion 50 adapted to contact the loadtransferring surface 42 of the bead seat member 24 when the tire rimassembly is assembled. A locating surface 52 is provided on the axiallyinner side of the split lock ring 28 and faces the open side of thegroove 34 in partial spanning relation to the first and second portion46,50 of the lock ring 28.

Referring now to FIG. 3, another embodiment of the invention isdisclosed. Common elements to those described in FIG. 2 will have likenumbers. A lock ring 54 is similar to the lock ring 28 except thelocating surface 56 of lock ring 54 has a protrusion 58 defined by thejuncture of the first and second portions 46,50 of the lock ring 54.

FIG. 4 illustrates another embodiment of the present inventionillustrated in FIG. 2. Elements common to those previously describedhave common numbers and elements that are modified will be representedby prime numbers. The outer periphery 30 of the rim base 18' defines afirst toric groove 32' adapted to receive an annular split lock ring 28'having a circular cross section. The bead seat ring 24' has a loadtransferring surface 42' adapted to mate with the annular split ring28'. A stepped inclined ramp surface 44' is defined on the bead seatmember 24' between the load transferring surface 42' and the innersurface 40. The locating surface 52' is defined by convex side portionof the annular split ring 28'.

Preferably the locating surface 52 of the annular split lock ring 28 istransverse to the outer periphery 30 of the rim base 18 with the annularsplit lock ring 28 in the installed condition. This provides a morepositive locating point for the elastomeric seal 26 to ensure propersealing of the second groove 34 and the inclined ramp surface 44 whenthe annular split ring 28 is in the installed condition.

Industrial Applicability

During assembly of the tire rim assembly 16, the second bead restrainingflange 22 is mounted axially on the rim base 18 and the tire 10 is thenaxially displaced on the rim base until the bead 14 engages the secondbead restraining flange 22 and the rim base 18.

The bead seat member 24 is then inserted axially between the rim baseand the tire bead 14 while the second bead restraining flange 20 isinserted between the tire bead 14 and the bead seat member 24 asillustrated in FIG. 1. After the aforementioned assembly, the tire bead12, first restraining bead flange 20, and the bead seat member 24 arefurther displaced in an axial direction toward the bead 14 for apredetermined distance such that the annular split lock ring 28 can beplaced in the first groove 32 and the elastomeric seal 26 can beinstalled in the second groove 34. After arranging the elastomeric seal26 and split lock ring 28 in their respective grooves, the bead seatmember 24, bead restraining flange 20, and bead 12 are allowed to moveto the right as shown in the drawing. Such rightward movement is inducedby the bead 12 seeking a return to its non-deformed position. Due to thesmaller size of the undeformed elastomeric seal 26 relative to the loadtransferring surface 42 of the bead seat member 24, the loadtransferring surface 42 does not engage the elastomeric seal during theaforementioned rightward movement. The rightward movement of the beadseat member 24 continues until the inclined ramp surface 44 engages theelastomeric seal 26 and causes the seal to contact the locating surface52 of the annular long ring 28 and elastically deform thus sealing thesurfaces between the elastomeric seal 26, the second groove 34, and theinclined ramp surface 44. Such elastic deformation due to thecompressive force continues until the load transferring surface 42 ofthe bead seat member 24 contacts the second portion 50 of the annularsplit ring 28 whereupon further rightward movement of the aforementionedcomponents is restrained and the annular split lock ring 28 is securedin the first groove 32.

If the seat surface 48 of annular split lock ring 28 is not in contactwith the outer periphery 30 of the rim base 18, the bead seat member 24will be moved towards the left due to the inclined surface of the loadtransferring surface 42 being in contact with the second portion 50 ofthe annular split lock ring 28. This leftward movement of the bead seatmember 24 will release the deformation on the elastomeric seal 26 thusthe sealing contact of the elastomeric seal 26 with the surface of thesecond groove 34 will no longer sustain air pressure in the tirechamber.

Furthermore, if the annular split lock ring 28 is not assembled duringthe initial assembly, the elastomeric seal 26 will move radially outwardand drop into the first groove 32 thus not allowing any air to bemaintained in the tire chamber. Since the first groove 32 has a depthand width greater than the diameter of the elastomeric seal 26, movementof the bead seat member 24 toward the rightward direction will not allowany contact at the location that the elastomeric seal 26 is in the firstgroove 32. It is recognized that the bead seat member 24 could contactthe elastomeric seal 26 in two places around the periphery of the firstgroove 32 if the elastomeric seal 26 is disposed outside of the firstgroove 32 on the opposite side of the rim base 18. Consequently, therightward movement of the bead seat member 24 will not allow any air tobe retained in the tire cavity. The inclined ramp surface 44 of the beadseat member 24 and the proximity of the elastomeric seal 26 with thefirst groove 32 does not allow the elastomeric seal 26 to be trappedbetween the inner surface 40 of the bead seat member 24 and the secondgroove 34 around the rim base 18. The elastomeric seal 26 will be merelypushed into the first groove 32 upon initial contact of the inclinedramp surface 44 with the elastomeric seal 26. Once the elastomeric seal26 drops into the first groove 32 the bead seat member 24 will notcontinue to move towards the rightward direction because there is notsufficient force in the tire chamber to continue the movement of thebead seat member 24.

From a review of the drawings it is readily apparent that theembodiments shown in FIGS. 3 and 4 function identically to thatdescribed in FIG. 2. In each case, if the annular lock ring 54,28' isinstalled properly or not installed at all the tire chamber will nothold inflation air pressure.

In view of the foregoing, it is readily apparent that the structure ofthe present invention provides an improved tire rim assembly that doesnot allow the tire to hold any inflation pressure if the annular splitlock ring is not properly installed or is omitted during assembly.

Other aspects, object and advantages of this invention can be obtainedfrom a study of the drawings, the diclosure and the appended claims.

I claim:
 1. A multiple-piece tire rim assembly (16) for mounting andsealing a tubeless tire (10), said tire rim assembly (16) comprising:anannular rim base (18) having an axial center line (19) and an outerperiphery (30) defining first and second grooves (32,34), said firstgroove (32) located in an axially outer portion of the outer periphery(30) of the rim base (18) and having a depth greater than said secondgroove (34), said second groove (34) defining a bottom surface and beinglocated axially inward of said first groove (32), said bottom surfacehaving a uniform diameter and opening into an inner side of said firstgroove (32); an annular bead seat member (24) disposed radially outsidesaid rim base (18) and having an inner periphery (38) radially adjacentsaid outer periphery (30) of said rim base (18), said inner periphery(38) defining an inner surface (40), a load transferring surface (42),and an inclined ramp surface (44) located between said inner surface(40) and said load transferring surface (42), said load transferringsurface (42) extending radially outwardly and upwardly from saidinclined ramp surface (44), said load transferring surface (42) and saidinclined ramp surface (44) being respectively radially adjacent saidfirst and second grooves (32,34); an annular split lock ring (28) havinga first portion (46) disposed in axially restraining engagement withsaid first groove (32) and a second portion (50) in load transferringengagement with said load transfer surface (42) of the bead seat member(24); and an annular elastomeric seal (26) having a cross section lessthan the width and depth of the first groove and being disposed in saidsecond groove (34) in axial abutment with the lock ring (28), saidannular elastomeric seal (26) being in sealing compression with saidsecond groove (34) by said inclined ramp surface (44) only when thefirst portion (46) of the lock ring (28) is fully seated in the firstgroove (32) and said load transferring surface (42) of the bead seatmember (24) is in contact with the lock ring (28) said annularelastomeric seal (26) freely moves from the second groove (34) to thefirst groove (32) during attempted inflation of the tubeless tire (10)in the event the lock ring (28) is omitted during assembly thus ensuringthat the tire cavity does not retain any air pressure during theattempted inflation.
 2. The multiple-piece tire rim assembly (16), asset forth in claim 1, wherein said first groove (32) has a toric surface(32') and said split lock ring (28) is circular in cross section (28').3. The multiple-piece tire rim assembly, as set forth in claim 1,wherein said annular elastomeric seal (26) is free from compression when(a) said load transfer surface (42) of said bead seat member (24) is outof contact with said split lock ring (28) and (b) said first portion(46) of said split lock ring (28) is partially out of said first groove(32).
 4. The multiple-piece tire rim assembly (16), as set forth inclaim 3, wherein said elastomeric seal (26) is circular in crosssection.
 5. The multiple-piece tire rim assembly (16), as set forth inclaim 1, wherein the second groove (34) has a width less than one andone half times the cross section of the elastomeric seal (26).
 6. Themultiple-piece tire rim assembly (16), as set forth in claim 5, whereinsaid width of the second groove (34) is substantially the same as saiddiameter of the elastomeric seal (26).